Added support for redirecting factories in dart api.

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_api.h"
 
 #include "platform/assert.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
@@ skipping 3537 matching lines @@
   if (::Dart_IsError(state)) {
     return state;
   }
 
   // Resolve the constructor.
   result = ResolveConstructor(
       "Dart_New", cls, base_constructor_name, dot_name, number_of_arguments);
   if (result.IsError()) {
     return Api::NewHandle(isolate, result.raw());
   }
-  // TODO(turnidge): Support redirecting factories.
   ASSERT(result.IsFunction());
   Function& constructor = Function::Handle(isolate);
   constructor ^= result.raw();
 
   Instance& new_object = Instance::Handle(isolate);
+  if (constructor.IsRedirectingFactory()) {
+    Type& type = Type::Handle(constructor.RedirectionType());
+    cls = type.type_class();
+    constructor = constructor.RedirectionTarget();
+  }
   if (constructor.IsConstructor()) {
     // Create the new object.
     new_object = Instance::New(cls);
   }
 
   // Create the argument list.
   intptr_t arg_index = 0;
   int extra_args = (constructor.IsConstructor() ? 2 : 1);
   const Array& args =
       Array::Handle(isolate, Array::New(number_of_arguments + extra_args));
@@ skipping 1135 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success(isolate);
 }
 
 }  // namespace dart